Following the highly growth of the semiconductor industry, the industrial safety issue draws more attention. In the semiconductor manufacturing process, it is needed to use a large amount of combustible, corrosive or toxic chemical materials. The remaining material that is not completely reacted in the process or the hazardous vapor evaporated in the reacting region is mostly transported to the facility exhaust system. The operator may be exposed to an environment contaminated by the toxic gases if the facility exhaust system is not adequately designed.
Among the semiconductor manufacturing processes, the CMP process is used for polishing a semiconductor wafer during the fabrication of semiconductor devices on the wafer. A wafer is “planarized” or smoothed one or more times during a fabrication process in order for the top surface of the wafer to be as flat as possible. CMP manufacturing applications range from microprocessors to Dynamic Random Access Memories (“DRAM”), flat panel display and multi-chip modules. As more manufacturing processes benefit from planarization, the safety and environment concerns for the CMP processes are raised.
For example, Ge and III-V materials are suitable candidates to replace Si as the channel material because of their intrinsic high carrier mobilities. However, these materials will release toxic gases (i.e. PH3 and AsH3) and hazardous byproducts (i.e. As2O3 and In2O3) during the CMP process and cause new problems to isolate and remove the toxic gasses and hazardous byproducts.
A complete CMP system consists of: a polisher, consumables, chemical distribution, cleaning systems, measurement, process isolation, an environmental control and a material handling system. A CMP system performs the CMP process in a polisher. The conventional polisher includes a door for isolating the chemical materials used in the CMP process from the outside environment, and a platen plenum that enables the operators to disassemble and maintain the polisher is configured below the polisher. Typically, the door of the polisher is made of the plastics and sealed by the sponge, which will cause the seal loss and cover damage after repeated use. Another disadvantage of the conventional polisher is that the door is opaque, which does not allow the operators to observe the process condition during operating and before open the door. Since the present CMP system does not provide a controllable processing environment or fails to avoid health and safety issues resulted from hazard and toxic CMP byproducts, so that providing a modified CMP system that properly manages controls and enhances the process environment is crucial.
The traditional CMP system does not have a good seal function and a monitoring function that ensure the process condition, and thus the toxic gasses often leak out of the polish chamber during the CMP process or outflow when the wafer is taken out by the operators. It is desired to ensure the environmental safety during the CMP process and before opening the door of the polisher in case that the operator may suffer from the toxic materials. Therefore, an improved CMP system is needed. For efficiently removing the byproducts, a modified CMP system is provided in this disclosure.
The current CMP system is a semi-open system kept at a minor negative pressure by the platen plenum exhaust connecting to the facility exhaust for removing the airborne byproducts. The platen plenum exhaust cannot efficiently pump out the byproducts. Moreover, the exhausted air contains huge moisture generated from the CMP process. The original design of the CMP system may incur water leakage resulted from moisture condensation and trap byproducts in the exhaust pipes resulting in a clogging issue. In order to enhance the moisture separating function of the CMP exhaust for removing moisture from the exhausted hazard byproducts (i.e. III-V compounds, RuO4 . . . ) and alleviating the leakage from the slits or cracks of the exhaust pipe, a CMP system with a moisture separator is also provided in this disclosure.
In view of the drawbacks of prior arts, there is a need to solve the above deficiencies/problems.